1. Field of the Invention
The intention relates to a drive train for a motor vehicle.
2. Description of the Related Art
DE 19841 330 discloses a supercharger to raise a charge pressure at the inlet side of the air system of an internal combustion engine to increase the power of the internal combustion engine. A secondary air pump also is used in the air system disclosed in DE 198 41 330 at a position upstream of a catalytic converter to blow secondary air into the outlet side of the internal combustion engine. As a result, the oxygen content in the exhaust gas is increased and the catalytic converter is heated up more quickly through post-combustion. A supercharger could be used instead of the secondary air pump. However, further valves and a relatively complex regulating system then would be required in the air system of the internal combustion engine to prevent an undesired additional charge pressure and a resulting excess torque of the internal combustion engine when the supercharger is used as the secondary air pump.
An object of the invention is to eliminate the secondary air pump from a drive train for an internal combustion engine that is supercharged by a supercharger, while modifying the air system as little as possible.